What should I do about my girfriend situation?

I had recently met this girl and we talked for a while & we soon got together but I found out that she was lying to me the whole time about her. She lives in different town than me, about 10 miles from me so I could see her if I wanted to but I had found out that she lied to me about her age & her grade. She told me she was 16 and in the 10th grade. I'm 17 in the 11th grade, so I didn't have a problem with it until some people that I knew had also knew her & told me she was lying. Turns out she is in the 7th grade & is like 13 or 14. After I figured she was lying I kept asking her things to see if she would confess but she kept up the lying and eventually I just asked her straight up. Long story short, I broke up with her because of it & she still wants to be with me & all. I think that the age & grade difference is a big problem. I really hate that she lied to me about that in the beginning cause if I had known then I wouldn't have even talked to her as if I were interested in her. She is attractive but the age difference just deters me from even considering talking to her like that. What should I do? Talk to her again or just forget about it & leave us as just friends and nothing more?